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R. NORDENSWAN AND R. C. WINCKEL.

TELEPHONE RECEIVER.

APPLICATION FILED JANA. 191B.

1,330,21 4. Patented Feb. 10, 1920.

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ROBERT NURIDENSWAN, 03% NEW ORK, 1%". "iii, RIGHARD G. XIVINUHEL, OF

. ELIZABETH, new .rnasrrr,

GNORE TQ W'EEEERN ELEC'IRKC CUMPANY,

INCORPORATED, OF NEW "213E152, 'SZZ, it. COEPGRATION 0]? NEW YORK,

inseam.

Specification of Letters Patent.

Application filed January 4, 1318. Serial No. eraser.

To all whom it may concern:

at Elizabeth, in the county of Union and State of New Jersey, respectively, have invented certain new and useful Improvements in Telephone-Receivers, of which the tollowingis a full, clear, concise, and exact description. 7

This invention relates to telephone receivers and more particularly to the magnet systems thereof.

An object cit this invention is to provide a magnet system oi increased elliciency for a telephone receiver by employing a pole-- piece material having a high permeability, which pole-piece is intimately united to the rest of the magnet system by a highly ellicient. and low reluctance joint.

Due to its high maximum permeability and its sharply defined permeability curve, which falls oft rapidly beyond the point oi maXimum permeability, it has been found that silicon steel is desirable for use in telephone receiver pole-pieces. It is, however, extremely diliicult owing to the physical characteristic of such material to join it to the tungsten or other magnet steel used for the permanent magnet by a joint having very loW reluctance.

In accordance with one feature of this invention, an intermediate member composed of soft iron is securely clamped to and intimately associated with a silicon steel polepiece by an embossing process and such soft iron member is welded to the adjacent end of the permanent magnet.

These and other features of the invention will more clearly appear from the following specification and annexed drawing showing a receiver illustrating the preferred embodiment of the invention and the parts entering into such a structure.

Figure 1 is a sectional view of the receiver with the magnet system partially in section and with one magnet coil omitted; Fig. 2 is an end View with the cap, a portion oi the diaphragm and one magnet coil omitted; 3 is a fragmentary perspective view before assembly of one pole-piece attached to its associated intermediate inember together with portions otthe cup and ot the permanent magnet; F 1g. lis a perspective view oi one pole-piece and its asso ciated intermediate member assembled; and l? 5 is a sectional view out the pole-piece and its intermediate member, along the line 5, 5 of Fig. 4e.

Beret-ring to the drawmga'l 18 a permanent magnet of tungsten or other magnet steel, each end or which is electrically weld ed to the projecting portion l of a soft iron intermediate or supplemental member 2,. Projecting portions 15, oil member 2/, are formed or bent around the silicon steel pole piece 3 and are further secured thereto by embossed portions 6, which engage corresponding apertures 8 in the polcpiece 3.

The inclosing cup 9 0i non-magnetic mate rial is provic ed with slots or perforations 10 through which the portions 4 extend, which portions are welded to the ends of the permanent magnet 1. The cup is clamped in position between the ends of the permanent magnet l and the adjacent ends of the pole-pieces 3, in cooperation with the extending portions 15 of the members 2. The pole-piece 3 is provided with the usual shoulders 7, serving; as a stop for the magnet coil 11. in the ordinary manner, diaphragm l2 rests upon the flange of the cup 9 and is clamped in position by means of the ear cap 13 cooperating with the easing it.

in practice the pole-piece 3 is placed within the intermediate member 2, the projections 15 are formed around the polepiece, and at points 6, are caused to ei'igage the apertures 8 of the pole-piece 3 by a staking or an embossing process. The resultant unitary structure, as shown in Figs. l and 5, is then placed in position with the portion of the intermediate member 2 extending through the slot 10 of the cup 9 and'the Patented lFeb. to, 1920.

adjacent end of the permanent magnet electrically welded thereto.

What is claimed is:

i. it magnet system for telephone ers comprising permanent magnet, a pole piece and an intermediate member secured to permanent magnet having a portion embracing and clamping said pole-piece 2. A magnet system for telephone rece1vers comprising a permanentmagnfi ak p l piece having anaperturetherem, andan 1n- 'termediate member secured to said permagaging such aperture.

4:. A magnet system for telephone receiverscomprising a permanent magnet, a polepiece and intermediate member secured to said permanent magnet having a portion embracing and clamping the pole-piece and a cup surrounding the p0le-piece, and secured in position by the cooperation of said permanent magnet, said pole-piece and said intermediate memberi.

5. A magnet system for telephone receivers comprising a permanent magnet, a cup having a slot therein and resting against the end of the magnet, a pole-piece and an intermediate member having a portion passing through the slot and secured to the permanent magnet and having another portion embracing and clamping said pole-piece and coiiperating With the magnet to clamp said cup in position.

6. A magnet system for telephone receivers comprising a permanent magnet, a cup having a slot therein, a p0lepiece having a plurality of apertures therein, an intermediate member having one portion thereof passing through the slot and welded to the permanent magnet, and having another portion embracing and clamping said pole-piece enga ing the apertures therein and cooperating therewith, and with the permanent magnet to clamp said cup in position.

7. A magnet system for telephone receivers comprising a permanent magnet, a pole piece and a member of'magnetic material interposed between said magnet and said pole piece, said member being secured to said permanent magnet and having portions embracing and clamping said pole piece.

8. A magnet system for telephone receivers comprising a permanent magnet, a pole piece and a member of magnetic material interposed between said permanent magnet and said pole piece, said member being secured to said permanent magnet and having portion embracingand clamping said pole piece, and a cup surrounding said pole piece and secured in position by the cooperation of said permanent magnet, said pole piece and said member.

In witness whereof we hereunto subscribe our names this 28th day of December, A. D.

ROBERT NORDENSWAN. RICHARD C. WIN CKEL. 

